Azo like emulsion in several grades

I am now able to make an Azo like emulsion in up to 7 contrast grades. This paper is about 1 stop faster than traditional Azo, and has a spectral sensitivity tilted more to the UV than visible region (less blue, more UV).

Some of the grades are designed to give a softer toe so that there is a longer tone scale with better highlight detail.

The range is obtained by use of one emulsion formula, but the use of variations in the final coating formulation, so that there is a minimum of lab work involved. In fact, with practice, you can make up one batch of melted emulsion and make 3 grades from it by adding addenda as you coat to vary the end result. So, make the melted emulsion, coat 10 sheets, add an ingredient, coat 10 more and add another ingredient and coat 10 more and you have 30 sheets of increasing contrast. Of course, by varying levels of these ingredients you can obtain custom results of intermediate contrast.

I have coated it on 4 types of paper. Strathmore Smooth, Vellum, Watercolor and Glossy Baryta. Difficulty increases in the order given, but sharpness is in the order Watercolor, Vellum, Smooth, Baryta in increasing order.

A coating defect appears on the left (soft grade) print which is not untypical of coating on Watercolor or Baryta.

I am posting two samples of a soft and hard grade on Watercolor. This particular paper has a rich surface similar to canvas, so the pattern you see is not a defect, but rather an artifact of the scanning process.

They were both exposed for 10" and developed in Dektol 1:3 for 1', followed by stop and fix. The fix was an acid hardening fix. I have used a variety of developer for processing this emulsion including the M&P Amidol developer. All work quite well.